1. Field of the Invention
The invention relates in general to a common-optical-path periscope, and more particularly, to a field-of-view driving structure and a focus driving structure of common-optical-path periscopes.
2. Description of the Related Art
The periscope used in the conventional armored vehicle is normally mounted on a turret, such that both the periscope and the bore of the artillery are driven by the turret. The typical periscope has a wide field-of-view and narrow field-of-angle output modes. By switching between these two output modes and performing a focusing operation, the output image is optimized. In the prior art, driving components for switching field of view and focusing can be designed in a whole single member, or in separate driving members. The single member design uses a 90xc2x0 rocker arm to change another set of lenses, so as to achieve the objective of switching field of view. The driving design for focusing includes rotating a guide bar by a motor, and driving a ring gear by the guide bar. The set of lenses is then adjusted by the displacement of the ring gear to achieve the objective of focusing.
Therefore, new-model periscopes usually have various kinds of optical output modes. For example, the periscope can be applied to extract different output modes of a visible charge-coupled device (CCD), a TTS and a LRF, optical sensing device in different wavelength bands, or the like. This common-optical-path periscope is a new type of periscope, in which different wavelength bands share the same common-optical-path before entering beam splitters.
However, the conventional field-of-view switching and focusing system, no matter the design integrating functions in one single member or with two functions in separate members, cannot be applied to the common-optical-path periscope.
The invention provides a switching field-of-view and coaxial focusing system suitable for using in a common-optical-path periscope that can perform fine focusing right after switching field of view.
The switching field-of-view and focus driving system of the common-optical-path periscope includes an aspherical reflecting mirror system, a field-of-view driving system and a focus driving system.
The aspherical reflecting mirror comprises a lens base, a lens frame, multiple resilient members, and multiple aspherical reflecting mirrors. The aspherical reflecting mirrors are mounted on the mirror frame, and the resilient member is used to suspend the mirror frame with respect to the mirror base. In addition, the mirror frame has a recess touched to the focusing driving system.
The field-of-view driving system is disposed at one side of the aspherical reflecting mirror system. Such field-of-view driving system is used to rotate the aspherical reflecting mirror system, such that one of the aspherical reflecting mirrors of the aspherical reflecting mirror system is facing the incident light. Using the field-of-view driving system to rotate the aspherical reflecting mirror system, different aspherical reflecting mirrors can individually face the incident light to achieve the objective of switching field of view.
The focus driving system is located at the other side of the aspherical reflecting mirror system to drive the aspherical reflecting mirror system moving along the optical path for fine adjustment of focus.
The field-of-view driving system includes a field-of-view driving motor, a first shaft, a worm gear and a shaft. The worm gear is driven to rotate by the first shaft, while the first shaft is driven to rotate by the driving motor. In addition, a second shaft is connected to the mirror base of the aspherical reflecting mirror system to rotate the mirror base.
The field-of-view of invention further comprises a first bearing and a first limit switch. The first bearing is fitted in the shaft, and the first limit switch is used to control the on/off state of the field-of-view driving motor.
The focus driving system comprises a focus driving motor, a third shaft, a worm gear, a lead screw, a slide, a limit pin, and a taper cam. The third shaft is driven by the focus driving motor to rotate. The worm gear is driven by the third shaft to rotate. The lead screw is driven by the worm gear to rotate, and the slide is driven to linearly move by the lead screw. The limit pin is disposed on the slide and move with the slide. The taper cam has one end in contact with the slide, and the other end in contact with the recess. The taper cam is rotated by the linear movement of the slide.
The focus driving system further comprises a bushing to enclose the slide of the focus driving system, the limit pin, the taper cam therein. The lead screw of the focus driving system sets inside the bushing, and the other end of the bushing attaches to the mirror base.
In addition, the bushing has a second limit switch therein, which combines with the limit pin to control the on/off state of the focus driving motor. The bushing further comprises a second resilient member with one end connected to an internal of the bushing, and the other end connected to the taper cam.
The focus driving system further comprises a second bearing fitted at a joint between the bushing and the lead screw.
The resilient members of the field-of-view and focusing system of the common-optical-path periscope include a spring.
Both the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the invention, as claimed.